108 THE JOURNAL OF BOTANY 
tion; but this view the author himself expresses. Certainly the 
Siac which he thus takes up makes the origin of the Algw more 
eens than has hitherto been indicated in any general. treatise 
upon t 
Though there is in the book only very sir iors to the 
chromosome. cycle (a matter on which the fact so W, w, and 
u 
developments. His recognition of the auxiliary cell, as a nutritive 
adjunct only, has tended to clear the obscurity which surrounded 
the sporogenous filaments, and confirmed the conception of them 
as a diffuse form of a post-sexual sporophyte 
Special chapters are devoted. to cell- structure, mode of nourish- 
ment, conditions of life, vegetative periods, and phenomena of 
stimulation of Alge; while, among their adaptive characters, their 
epiphytic, endophytic, and parasitic habit, as well as their symbiotic 
relations, The pe concludes 
with a short section on methods of collection and of treatment. 
n as a whole, this new work is the most Seba and 
complete treatise on Alge hitherto produced. be an 
essential part of the outfit of any algologist. The. Beenanony 
are far-re , and the criticisms of the work of others sing 
fi hey are marked by an international sonality 
which is theoretically present. in all scientific work, eh in this 
h 
while the pre spirit of the whole work semaines him to pass 
beyond them by personal researc 
The pu ablianees have given the book every chance by type and 
illustration. It might be wished, however, that the weight of 
learning which it contains were not so practically prefigured by the 
heavy mineralized paper upon which this excellent work is printed. 
F. O. Bower. 
Minnesota Plant Diseases. By Dr. EK. M. Freeman. - St. Paul, 
Minnesota. 1905. Pp. xxiii and 482. 
TuerE is, perhaps, no branch of botany to which more atten- 
tion is given at the present time in pec agar d on the Continent 
than that of Leven diseases caused by parasitic fun, ngi. The panes 
is of great economic importance, and the orators in the form of 
papers, ecllstins, reports, &c., increases enormously. Dr. Frosh 
